UPS & 3B1 Anecdote

[Boyd Ostroff]

In article <4623 at daffy.cs.wisc.edu> horn at rt5.cs.wisc.edu (Mark Horn) writes:
>In article <4491 at cbnewsj.ATT.COM> gnome at cbnewsj.ATT.COM (ronald.l.fletcher) writes:
>I think Boyd Ostroff said that his power supply was 386 Watts (?).  Well, then
>if the UNIXPC draws .86 Amps, what does this translate into for a reasonable 
>UPS?  Say I want one that will last XX minutes, how do I translate .86 Amps into
>XX minutes?  I assume that the rating on the power supply has everything to do
>with it.  

Actually it's 325 watts.  The duration that you get has nothing to do with the
wattage rating, though.  The wattage (or volt-amps) just tells you how
big a load you can plug into it without blowing the inverter.  It would be
wasteful to buy a unit with a higher wattage rating than you need; actually
you're interested in battery capacity (amp-hours).  Find out the amp-hour
rating of the battery and divide it by the current draw of your equipment.

Tripp-Lite makes another series which come without batteries and you supply 
your own (or buy one of theirs).  If you need capacity, you might check these 
out - get your own cheap car (or boat) battery and hide it under your desk.  
I bought mine mainly on price.

I circled all the appropriate items on one of those magazine "reader service 
cards" before I bought my UPS and got tons of catalogs and spec sheets back in
the mail (including a newsletter from some company that I still receive
showing monster installations at radio stations, etc :-).  These spec sheets
will tell you everything you want to know (and more) about battery capacity,
transfer time, waveform, etc.

||| Boyd Ostroff - Tech Director - Dept of Theatre - SUNY Oswego 
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